/**
* Copyright 2010 The Apache Software Foundation
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.alibaba.wasp.jdbc.value;
import com.alibaba.wasp.jdbc.JdbcException;
import com.alibaba.wasp.util.SmallLRUCache;
import java.text.CollationKey;
import java.text.Collator;
/**
* The default implementation of CompareMode. It uses java.text.Collator.
*/
public class CompareModeDefault extends CompareMode {
private final Collator collator;
private final SmallLRUCache<String, CollationKey> collationKeys;
protected CompareModeDefault(String name, int strength) {
super(name, strength);
collator = CompareMode.getCollator(name);
if (collator == null) {
throw JdbcException.throwInternalError(name);
}
collator.setStrength(strength);
int cacheSize = 32000;
if (cacheSize != 0) {
collationKeys = SmallLRUCache.newInstance(cacheSize);
} else {
collationKeys = null;
}
}
public int compareString(String a, String b, boolean ignoreCase) {
if (ignoreCase) {
// this is locale sensitive
a = a.toUpperCase();
b = b.toUpperCase();
}
int comp;
if (collationKeys != null) {
CollationKey aKey = getKey(a);
CollationKey bKey = getKey(b);
comp = aKey.compareTo(bKey);
} else {
comp = collator.compare(a, b);
}
return comp;
}
public boolean equalsChars(String a, int ai, String b, int bi, boolean ignoreCase) {
return compareString(a.substring(ai, ai + 1), b.substring(bi, bi + 1), ignoreCase) == 0;
}
private CollationKey getKey(String a) {
synchronized (collationKeys) {
CollationKey key = collationKeys.get(a);
if (key == null) {
key = collator.getCollationKey(a);
collationKeys.put(a, key);
}
return key;
}
}
}